The present invention relates to a shunting device and more particularly to a device used on railroad maintenance vehicles for making electrical contact with the railroad track to operate signaling devices and communication with a railroad dispatcher.
Shunting devices are used on railroad maintenance vehicles. These vehicles are typically pickup trucks, stake truck and other types of trucks used on the highways. High rail attachment units are usually attached near the front and rear bumper of the vehicle. The high rail attachment unit contains wheel assemblies that align with the railroad track. The high rail attachment unit is lowered as the maintenance vehicle is positioned over the railroad track. The wheel assemblies engage the railroad track to allow the vehicle to be driven on the tracks.
Electrical signals are transmitted through the track to control signaling devices and for communication with the dispatcher. The dispatcher knowing the track is occupied can route trains around the occupied track or take other precautions. Shunting devices provide an electrical contact from a signal generator in the vehicle to the track. Typically, a shunting device will be used at each wheel assembly to provide multiple contact points. Independent signals can be given to each tracks or the track can be shorted as needed.
Electrical signals have to be given on a continuous basis or at predetermined intervals to prevent accidents and operate signaling devices. To ensure that the signal can be given at the correct time, there must be a continuous electrical contact between the signal generator and the track. The shunting devices must also be electrically isolated from each other so independent signals can be given to each track. Railroad tracks may also have irregularities, unevenness, obstacles, rust and other electrical obstructions. The shunting devices must overcome these obstructions to provide electrical contact with the track. Additionally, larger obstructions may damage the shunting device, high wheel attachment unit or the vehicle. Therefore, a safety means must be provided to prevent undue damage. Since these devices are in constant contact with the railroad track, as the vehicle is driven up and down the railroad track, the shunting devices are being continuously worn down. A means of adjusting for continuous wear must be provided to ensure the continuous contact with the track.
Accordingly, it is an object of the present invention to provide a shunting device that is easily attached to a high wheel attachment unit to make a continuous electrical contact with a railroad track.
Another object of the present invention is to provide an improved shunting device constructed to provide a means of adjusting for continuous wear and for rust and other obstructions on the railroad track while maintaining a continuous electrical contact with the track.
A further object of the present invention is to provide a shunting device adapted for easy adjustment once mounted or attached to a high wheel attachment unit to increase the assurance of continuous electrical contact with a rail.
Still another object of the present invention is to provide a shunting device that is electrically isolated from the vehicle and from each other and to provide a safety break to prevent damage to the shunting device, high wheel attachment unit and the vehicle.